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为满足实时业务的QoS要求,在非延迟受限组播路由算法(Fast Low-cost Shortest Path Tree,FLSPT)的基础上添加了延迟约束,使得生成的组播树上,每条从源到目的地的路径都满足给定的延迟限制,同时保持了原算法计算复杂度低,代价性能优越的特点。仿真结果表明,本文算法的代价和时间性能均优于延迟受限最短路径(Delay-Constrained Shortest Path, DCSP),且更适合用于目的节点分布集中的密集模式下。 相似文献
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本文给出了时延约束组播路由问题的数学模型,提出了一种分布式、收敛快、支持动态组播的时延约束组播路由算法--DMPH(Delay-constrained Minimal-cost Path Heuristic),分析表明采用该算法具有良好的网络开销性能. 相似文献
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在实时性要求比较高的应用中,时延要求限制了sink的移动速率与移动轨迹,sink的移动速率限制了节点与sink的通信时间,因此很难兼顾时延要求与数据收集效率。提出一种时延受限的移动sink数据收集算法MSDC,在低能耗缓存区内找到一条sink的最优移动轨迹,在有限的时间限制内利用sink的移动性来提升传感器网络的数据收集性能。仿真结果表明,与已有算法比较,该方案能够提高网络数据采集量,降低能耗,延长网络生命周期。 相似文献
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Many Wireless Sensor Network (WSN) systems are deployed in unattended areas using non-rechargeable batteries. To enable sustainable operations, most WSN systems employ duty-cycling mechanisms, such as Low Power Listening (LPL). For reliable delivery of each packet with LPL, the sender has to transmit a preamble that is long enough to span over a complete sleep interval of the receiver. In this way, the sensor nodes avoid idle listening, however, at the cost of remarkably increased end-to-end delay of multi-hop packet transmissions. To address this issue, in this paper we propose a new duty-cycling mechanism called DC-Gear. DC-Gear exploits a“sleep less but save more” phenomenon, which means increasing the duty cycle in a timely and appropriate manner while minimizing the overall energy cost and satisfying the end-to-end delay constraint. We have implemented DC-Gear with TelosB motes and demonstrated its performance advantages through extensive experiments. 相似文献
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This paper is concerned with a restricted version of minimum cost
delay-constrained multicast in a network where each link has a delay and a
cost.
Given a source vertex $s$ and $p$ destination vertices
$t_1, t_2, \ldots, t_p$ together with $p$ corresponding nonnegative delay
constraints $d_1, d_2, \ldots, d_p$,
many QoS multicast problems seek a minimum cost multicast tree in which
the delay along the unique $s$--$t_i$ path is no more than $d_i$ for
$1 \le i \le p$.
This problem is NP-hard even when the topology of the multicast tree is fixed.
In this paper we show that every multicast tree has an underlying Steiner topology and that
every minimum cost delay-constrained multicast tree corresponds to a minimum
cost delay-constrained realization of a corresponding Steiner topology.
We present a fully polynomial time approximation scheme for computing a
minimum cost delay-constrained multicast tree under a Steiner topology.
We also present computational results of a preliminary implementation to
illustrate the effectiveness of our algorithm and discuss its applications. 相似文献
7.
探讨了带时延约束组播路由优化算法,选用时延约束信息产生备选路径集并编码,给出了在该编码方式下使用不同进化阶段应用不同变异概率思想的改进遗传算法.仿真试验结果表明,该算法是可行有效的. 相似文献
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A Polynomial Time Approximation Scheme for Minimum Cost Delay-Constrained Multicast Tree under a Steiner Topology 总被引:1,自引:0,他引:1
This paper is concerned with a restricted version of minimum cost
delay-constrained multicast in a network where each link has a delay and a
cost.
Given a source vertex $s$ and $p$ destination vertices
$t_1, t_2, \ldots, t_p$ together with $p$ corresponding nonnegative delay
constraints $d_1, d_2, \ldots, d_p$,
many QoS multicast problems seek a minimum cost multicast tree in which
the delay along the unique $s$--$t_i$ path is no more than $d_i$ for
$1 \le i \le p$.
This problem is NP-hard even when the topology of the multicast tree is fixed.
In this paper we show that every multicast tree has an underlying Steiner topology and that
every minimum cost delay-constrained multicast tree corresponds to a minimum
cost delay-constrained realization of a corresponding Steiner topology.
We present a fully polynomial time approximation scheme for computing a
minimum cost delay-constrained multicast tree under a Steiner topology.
We also present computational results of a preliminary implementation to
illustrate the effectiveness of our algorithm and discuss its applications. 相似文献
10.
通过对时延约束组播路由网络模型的分析,提出了一种基于拉格朗日松弛法的时延约束的低代价组播路由算法(LR-DLMR)。由于封闭图对原网络的多播不可达问题,该算法并没有构建原网络的封闭图,从而有效利用了链路中间节点信息。仿真实验结果表明本算法具有良好的稳定性,有较低的代价和时延。 相似文献